Tekkaman-James: In order for anyone to properly troubleshoot your problem, you would need to provide a bit more information. Most importantly would be which operating system you are playing the game on. When asking for help, it is better to give too much information than too little.
Alternately, you can contact GOG's support team directly by filling out the form found
HERE. It might take them a day to get back to you
(mostly due to time zone differences), but they will do their best to get the game working for you.
Same issue here. Windows 10, 64 bits. RAM 64 GB. Nvidia Geforce GTX 780.
Not working in the windowed/full mode, neither the low resolution mode, neither changing the resolution, neither wiht the "run as administrator" option.